1. Technical Field
The present invention relates to a manufacturing apparatus of a bonded member and a manufacturing method of a bonded member. More particularly, the present invention relates to a manufacturing apparatus of a bonded member and a manufacturing method of a bonded member for bonding two substrates as the bonded members together adjusting a curing state of a resin film.
2. Related Art
Conventionally, when manufacturing the bonded member, particularly an optical device with the substrate in non-circular shape such as a liquid crystal panel, resin has been applied in a so-called fishbone shape, and the substrates have been bonded together. In other words, bonding has been conducted by applying the resin that becomes a major section around a center of one substrate, applying the resin as plural guidance sections branching from the major section toward the outer periphery of the substrate, placing the one substrate to face to the other substrate, and gradually moving the substrates close to each other to spread the applied resin over the entire substrate. (See Patent Documents 1 and 2)
FIG. 18 schematically shows a conventional bonding method. In bonding of comparatively thick substrates 11E and 12E, when the substrates are provisionally bonded by irradiating ultraviolet light from cutout sections 17E at four corners of the holding means 41E with an ultraviolet irradiation means 31E in a state where one substrate 12E is held with a holding means 41E, the initial state of two combined substrates 11E and 12E could be maintained even if the held state is cancelled after bonding.
[Patent Document 1]                Japanese Patent Application Publication No. 2011-22508        
[Patent Document 2]                Japanese Patent Application Publication No. 2011-67802        
However, if at least one of the two substrates is thin, it has been difficult to maintain uniform film thickness after bonding. For example, due to the shape of a holding surface or the presence of absorption holes of the holding means, distortion occurs on a surface of the film-like substrate, and the uniformity of the film thickness is largely affected.
The following problems arise when the film-like thin substrate is provisionally bonded by the irradiation of the ultraviolet light from the cutout sections 17E at four corners of the holding means 41E with the ultraviolet irradiation means 31E in a state where the film-like thin substrate is held in the holding means 41E by the conventional holding means. In other words, the light incident from a space between an end of the holding means 41E and the substrate 11E into the inside of the substrate is dispersed between the holding means 41E and the substrate 11E, or the area where the ultraviolet light is blocked and the area where the ultraviolet light is irradiated are produced, and therefore the differences in amount of irradiation of the ultraviolet light arise, and nonuniform curing occurs on a resin film 13E. Thus, there has been a problem that the distortion (undulation) occurs on the surface of the film-like substrate and the uniform film thickness cannot be maintained.
In a curing process of the resin film after bonding, if the holding means 41E holding the film-like substrate could be removed and the film-like substrate could be cured without being held, the holding member 41E might not be an obstacle, and the resin film 13E could be uniformly cured. However, there has been a problem that when the holding member 41E is removed from the film-like substrate, the film-like substrate combined at an optimum position on the substrate 11E becomes misaligned.
In addition, when a relative misalignment is present between the substrates, or when the distortion (undulation) occurs on the surface of the film-like substrate and the film thickness becomes nonuniform, it results in significant reduction of visibility and in disfigurement. Furthermore, in a case where a touch panel as the film-like substrate is bonded to the substrate, the sensitivity of a touch sensor becomes non-uniform.
The object of the present invention is to prevent the relative misalignment from occurring between the substrates, to prevent the distortion (undulation) from occurring on the surface of the thin substrate, and to achieve the uniformity in the film thickness in a case where one of the substrates is a thin substrate when two substrates are bonded together to produce the bonded member.